This invention relates generally to flat panel display devices and particularly to a unitary beam guide/electron gun assembly for such devices.
U.S. patent application Ser. No. 116,251 filed Jan. 28, 1980 by Charles B. Carroll entitled "Baseplate Assembly For Flat Panel Display Devices" discloses a flat panel display device including an electron gun section having a line cathode and a modulator. The display device includes a display section which is divided into a plurality of channels along which electron beams are propagated. A display screen is arranged along one inside surface of the display section and when a particular line of the visual display is to be generated, electron beams propagating in the channels are deflected to strike the display screen. Accordingly, each of the channels contributes a portion of each of the lines across the display screen.
Each of the channels includes a beam guide assembly having a pair of spaced parallel guide meshes, a focus mesh and an acceleration mesh which are in a spaced parallel relationship with respect to the guide meshes. The electron gun section includes a modulator support, having a plurality of retention recesses which receive retention tabs integral with the beam guide assemblies. The line cathode within the electron gun section is precisely positioned with respect to the modulator support and the beam guide assemblies so that electrons from the cathode enter the spaces between the guide meshes for propagation along the channels.
In Assemblying the Carroll display device, the modulator support is precisely located with respect to one inside surface of the display section. The line cathode is then located with respect to the modulator support. The beam guide assemblies are attached to the modulator support by mating the retention tabs and the retention recesses. The retention recesses are precisely located along the modulator and, therefore, the beam guide assemblies are precisely located with respect to the modulator support. Accordingly, the beam guide assemblies and the cathode are positioned with respect to one another because they both are referenced to the modulator support.